Looking for advice/comments on suitability of an economical DIY machine for engraving fine text on plastic (PTB Polyester), example in below image file. I am not experienced in tradeoffs for laser engraving but am technically able to fabricate and assemble a DIY cnc machine.

The engraving area in image is approx 1.1in x 0.6in and I will be arraying parts in batches of 100ish pieces.

Require excellent clarity/crispness of text so looking for best dots per inch resolution. Does this require a short focus lens such as F38.1mm?

Considering building the new PR530 as a DIY with a 40 or 45W tube using parts list posted by Marco. Is PR350 suitable or overkill for my application?

Would a D/K40 with LO upgrades be suitable for my application?

Any other suggestions for economical platform with excellent resolution?

A regular CO2 laser won't be able to handle this kind of engraving. You need a label 'marking' machine instead. It is similar to a fiber optics laser machine but with different light spectrum. It won't be cheap through. Be expecting price range at $6500~$9,000.